Carbohydrates and GI

did you know

Low-GI foods aren’t just important for children and adults with diabetes – they can be part of healthy, well-balanced daily eating for everybody.

Our bodies get energy by turning carbohydrates into simple sugars. Different carbohydrates are broken down into sugars at different rates, and glycaemic index (GI) is how we measure this. Low-GI foods give your child longer-lasting energy.

What are carbohydrates?

Carbohydrates are natural substances that contain oxygen, hydrogen and carbon. We need carbohydrates to give our bodies energy – to ‘get up and go’.

We get carbohydrates from:

starchy foods like bread, pasta, rice, cereals and potato

fruit and vegetables

dairy products like milk and yoghurt.

We also get carbohydrates from table sugar and sugary foods like ice-cream, biscuits, soft drinks and cakes.

What is glycaemic index (GI)?

When we eat carbohydrates, our digestive system breaks them down into simple sugars – mainly glucose. Our cells use this glucose to produce energy.

Carbohydrates break down into glucose at different rates. This means that different carbohydrates – that is, different foods – cause glucose levels in our blood to go up and down at different rates.

The glycaemic index (GI) measures the effect that carbohydrates in food have on blood glucose levels. GI ranks foods on a scale from 0-100:

Foods with a low GI (0-55) cause a steady and long-lasting rise and fall in blood glucose levels. This is because the carbohydrates in these foods break down slowly.

Foods with an intermediate GI (56-69) cause a moderate rise and fall in blood glucose because their carbohydrates break down at a moderate rate.

Foods with a high GI (70-100) cause a large and fast rise and fall in blood glucose. This is because the carbohydrates in these foods break down quickly.

Low-GI foods are broken down slowly for steady, long-lasting energy. If your child eats more low-GI foods than high-GI foods throughout the day, it’ll help keep her energy levels steady.

Foods and GI

The following is a guide only to some foods and their GI values. Different varieties and brands of food can have different GI values, so it’s best to speak to a dietitian if you’d like more information.

Low-GI foods (GI of 55 or less)

Intermediate-GI foods (GI between 56 and 69)

High-GI foods (GI of 70 or more)

Barley

Bran

Carisma potatoes

Dense wholegrain bread

Doongara rice

Fruits and vegies (except melons and most potatoes)

Legumes

Milk

Natural muesli

Pasta

Pearl couscous

Quinoa

Yoghurt

Traditional oats

Raisins

Rice (basmati, arborio and long grain)

Soft drink

Sweet biscuits and cakes

Wholemeal bread

Hot chips/French fries

Jasmine rice

Lollies

Most breakfast cereals (for example, flaked corn and puffed rice)

Most crackers and savoury snacks

Potatoes

Sport drinks

White bread

Low-GI symbolWhen you’re looking for low-GI food, it’s also a good idea to look for the Glycemic Index Foundation’s Low-GI symbol. Many foods are now marked with this symbol. Foods with the symbol must be low GI and meet strict standards for kilojoules, fat, saturated fat, sodium and, where appropriate, fibre and calcium.

Benefits of low-GI food

Low-GI foods are good because they give your child longer-lasting energy, which can help him concentrate better and keep him going for longer.

Low-GI foods also keep your child feeling fuller for longer. This can help him maintain a healthy weight.

Using GI to plan healthy family eating

As well as making sure your family eats plenty of fresh food from the five healthy food groups, it’s good to think about GI when you’re planning what your family will eat.

Getting a balance of high and low GI
Low-GI foods are generally healthier than high-GI foods. This is because low-GI foods make blood glucose (sugar) levels go up and down slowly and steadily. This means your child is fuller for longer, so she’s less likely to snack between meals and overeat.

It’s OK to eat some high-GI foods occasionally. The trick is to include a low-GI food for your family at each meal and snack.

High-GI foods and low-GI foods combine in your child’s body for a medium GI – they balance each other out.

Quantity matters
When you’re choosing which foods to offer your family, it’s important to think about not just the GI rating, but how much of these foods you’re eating – that is, portion size. This is sometimes called the glycaemic load (GL).

A big serving of a high-GI food like potatoes or lollies will have a big impact on your child’s blood glucose levels. So if your child has small serves of high-GI foods and larger, more frequent serves of low-GI foods, this can balance things out.

When to eat your carbohydrates
There’s no hard and fast rule about when to eat carbohydrates, but each day it’s good for your child to have three regular meals and some nutritious snacks. This way, your child gets an even spread of carbohydrates across the day.

This keeps your child’s blood glucose levels stable and his energy levels steady. This is essential for adults and children with diabetes, but it’s also important for people who want to keep up good general health.

Your child’s total carbohydrate needs depend on how much physical activity your child does and how old she is.

Making the change to low-GI foods

Switching to low-GI food is easy. Chances are your family won’t notice the difference – at least not all of the time.

By swapping at least half your carbohydrate food choices for lower-GI options, your whole family can reap the benefits.

white potato for low-GI potatoes like Carisma™, and sweet potato, corn, pasta or legumes like lentils, beans and chickpeas

most rices for Basmati, Doongara or Mahatma rice.

Some foods with lots of fibre can help slow the breakdown of carbohydrates, giving it a lower GI. By choosing wholegrain foods or keeping the skin on vegies like potatoes and carrots, you can get your family eating more low-GI foods.

Frequently asked questions about low-GI foods

What if my child doesn’t like low-GI foods?
Not all of your child’s food needs to be low GI. Low-GI and high-GI foods combine to give a medium GI – they balance each other out. Ideally, at least half of your child’s carbohydrates will come from low-GI foods he enjoys.

You can try to:

set a good example and show your child that you enjoy eating lots of different low-GI foods

keep offering low-GI foods at mealtimes and encourage your child to taste them – it might take up to 10-15 times before she accepts new foods and flavours

Chocolate has a low-GI value. Does this make it a good food choice?
Many foods high in fat have a lower-GI value – chocolate is a good example of this. Low GI doesn’t cancel out the problems of high fat – you need to look at the whole food.

So you and your family should try to have foods like chocolate as occasional treats only.

What’s the best food for my child to eat before sport?
Carbohydrate foods are the best source of energy before sport. Low-GI breakfast foods – like traditional porridge, wholegrain cereal or toast – will give your child sustained energy on the day of the game.

GI and diabetes

If your child has type-1 diabetes or impaired glucose tolerance, his blood glucose levels might rise above a normal level more quickly than other people’s.

Eating low-GI foods can help your child manage her blood glucose levels. And eating moderate amounts of low-GI foods regularly over the day will help her keep consistent blood glucose levels.

If your child has a medical condition like diabetes, it’s important to talk with your GP, dietitian or specialist before making any changes to his eating.

There’s no link between eating sugar and developing diabetes. But eating too much added sugar can contribute to weight gain, and being overweight increases the risk of developing type-2 diabetes.

Anderson, J.W., Randles, K.M., Kendall, C.W., & Jenkins, D.J. (2004). Carbohydrate and fiber recommendations for individuals with diabetes: A quantitative assessment and meta-analysis of the evidence. Journal of the American College of Nutrition, 23(1), 5-17. doi: 10.1080/07315724.2004.10719338.